ringing the magnetospheric bell

Hi, my name is Rod. If you've already followed Ros's adventure (Earth Under Attack), you'll know that the Earth is surrounded by a large magnetic field. This region of magnetism is known as the magnetosphere, and it shields us from the stream of ionised gas flowing towards us from the Sun, the so-called solar wind.

I study the effect the solar wind has on the magnetosphere and what it means for you, me and the rest of life on Earth. I look at how changes in the solar wind make the Earth's magnetic field 'wobble' and how waves are created within it.

The wind blowing out from the Sun does not always flow at the same speed. It changes as a result of events taking place on the surface of the Sun, such as coronal mass ejections and solar flares

The picture to the right is of a coronal mass ejection and was taken by the LASCO telescope on board SOHO. These are big events, which, from an astronomer's point of view, are happening right on our own doorstep. They must have an effect on Earth and it's my job to find out what those effects are.

The solar wind itself is made up of fast-moving particles. As they bombard the magnetosphere, some of them set up waves in the Earth's magnetic field. It's a bit like a storm at sea when the wind blows hard and creates massive waves. By measuring lots of these magnetic waves, we can work out where the solar wind particles like to hang out and how they move about.